benjamin



Patented July 29, I919.

NE R\ 3 3 SHEETSSHEET I.

G. H. BENJAMIN.

TUNNEL KILN.

APPLICATION FILED JUNE 27,1917.

G. H, BENJAMIN.

TUNNEL KILN.

APPLICATION FILED JUNE 27. 19x7.

lutm'lted July 29, 19M

3 SHEETSSHEET 3.

' a high temperature,

posed to a very high "1% i an TL-KILN.

LSiiiAidi".

Specification of Letters iatent.

Patented July as, rare.

Application filed June 27, 1917. Serial No. 177,212.

To all whom it may concern:

Bev it known that I, Gannon HILLARD BEN- mmirn a citizen of the UnitedStates, residmg at New York, in the county and State of New York, haveinvented certain new and useful Improvements in Tunnel-Kilns, of whichthe following isa specification.

My invention relates to tunnel kilns of the type especially designed.for the treatment of bath tubs or other apparatus where heat theapparatus to then apply a coating without removing the apparatus fromthe kiln, and then again heatm to vitriiy the coatin to produce an enameedsurface.

in a l kilns of which i am aware, which have been designed for thepurpose the following objections apply.

First: When the apparatus under treatment is moved out-of the chamberwhere it is preliminarily heated, and into a position where the coatingcan be applied, the workmen who apply the coating are eitherextemperature, which is injurious t their health, or the apparatus toso-low a temperature that the coating material which is usually siftedon the apparatus, will not adhere.

Second: When the apparatus under treatment is moved into it is desiredto first stated,

the coating position, and no means are provided for closing thepreliminary or secondary heating chambers, these chambers are cooled,which not only involves a loss of heat, but frequently produces checkingor distortion of the apparatus under treatment in the chambers.

My improved kiln and method of treatment is designed to overcome theobjections stated, in that both the preliminary and sec ondary heatingchambers are provided with doors which act as closures for the chambersand thus secure the maintenance of fixed temperatures in the chambersand also prevent the heat from the chambers being radiated into thechamber in which the coating operations are carried on. Further, thechamber in which the coating operations are carried on, is ,providedwith doors, which prevent the heat from the preliminary and secondarychambers flowing into the coating chamber during the time the apparatusare moved from the prelimina heating chamber into the coating cham r,and out of the coating chamber into the secondary chamber, and alsoprevent access of external air into the coating chamber from illustratemy improved kiln,

the coating chamber into the preliminary and secondary chambers.

I wish it understood that the doors or closures for the preliminary andsecondary chambers and for the coating chamber, may be modified fromthose shown, both as to construction and method of operation, withoptdeparting from the intent of my invention.

. The method of operation involved in my improved kiln consists in firstheating the apparatus under treatment in the preliminary chamber, to adesired temperature;

then moving the apparatus into the coating chamber and thereapplying'the coating material without exposing the apparatus to conditions which would involve a considerable loss of temperature; paratusinto the secondary chamber; then heating to a temperature sufficient tomelt or fix the coating; 1

The accompanying drawings will serve to in which Figure 1 is ahorizontal section.

Fig. 2 is .a vertical section taken on the line 11-11 of Fig. 1.

Fig. 3 is a vertical section and partial elevation taken substantiallyon the line III-J11 of Fig. 2

Fig. 4 is a vertical section taken on the line IV-IV of Fig. 1.

Fig. 5 is a transverse section taken on the line VV of Fig. 2.

Referring to the drawings. 5 indicates the bod of the kiln. The body ofthe kiln is divi ed into three chambers. arranged in line-A, thepreliminary heating chamber; B, the secondary chamber; C. the coat--ingi chamber. Located at the front and rear en s of the preliminary andsecondary heat ing chambers A and B, are doors D, D. D D These doors areadapted to reciprocate to open and close the chambers by, means of thepistons E, E EQE The coating chamber C is divided into three chambers,the central chamber C and two side chambers C Doors F--F' in pairs, areprovided for the purpose of separating the chamber C from the chambers CThe doors in the drawing which are shown in full lines, assumes that thechambers C and C are in connection, and in dotted lines assumes that thechambers C and C are separated. The chambe s C are provided with doors Gthrough which access may be had to the chambers .1.

then moving the ap- The truck 8 18 shown as carrying two bath tubs. Inthe drawings, three trucks, each carrying two bath tubs, are shown aslocated in the preliminary and in the secondary chambers A and B. a

The means for heating the chambers may be of any construction which isfound suitable. That disclosed in the drawings has been made the subjectof a prior application and therefore will only be generally described.The heating apparatus, as shown, consists of hot blast stoves 10, 10,11, 11 arranged'in pairs on opposite sides of the 1 preliminary andsecond heating chambers.

p of the comply pipe 17 (see Fig, 1)" provided with athe two hot blastThese hot, blast stoves are of the usual construction given to suchapparatus, and each consists of a combustion chamber, 12, a heatingchamber 13, a gas pipe 1 1, an air pipe 15,amixin pipe ustion chamber, adry air supvalve 1'? also leading into the bottom of the combustionchamber, an exit pipe 18 having two branches, one branch 19 connected tothe chimney flue 20, and one branch 21 connected to flues 22 and 31 inthe side walls of the chamber 6. A butterfly valve 23, situated in thepipe 18, has for direct the body passing through the hot blast stoves,either through pipe 19 to chimney flue 20 (products of combustion) orwhere the posljtiomof the valve is shifted, through pipe 21 to flues 22and 31 in the walls of the kiln (hot air currents).

It will be seen by reference to the drawings '(Fi 1) that when thebutterfly valve is in t e position shown, the two hot blast stoves 10and 11- at the left hand end of the chambers A and B are deliveringproducts of combustion to the chimney flues 20, while stoves 10 and 11at the right hand end of chambers A and B aredelivering heated air tothe flues 22 and 31.

e operation of the hot blast stoves will be readily understood. Gas andair is intro duced through The products of combustion from the chamber12 pass upward and then downward through the heat' ing chamber 13, andthen out through pipes '18 and 19 to chimney flue 20, heating thestructure of the heating chamber 13 during their passage. When theheating chamber has been brought to the required temperature, thebutterfly valve 23 is shifted, the

gas and air shut ofi through pipes 14, 15 and 16 and yalve 17 in pipe 17opened, which allows air to enter through the pipe 17. The

16 leading into the bottom through its purpose tov pipes 14, 15 and 16'into the I chamber 12, then burned.

air entering, passes up the combustion chamber 12, down the heatingchamber to pipe 18, through pipe 21 to flues 22-31 in the body of thekiln. In order to aid in heating the heating chamber 13, the to of allthe hot blast stoves are connected b which are valves 2526. The pipe24-is also connected through pipes 2728 with combustion chambers 29, 2930, 30*, located within the body of the kiln. -With the butterfly valvein the position shown in Fig. 1, the valve 25 in pi e 24 will be openedand the valve 26 closed Hence the products of combustion from within thecombustion chambers 29, 29 30, .30, will flow through pipe 27 to pipe 21-, thence through the heating chamber 13 to chimney flue 20,'theproducts of combustion aiding to heat the chambers 13.

It is not essential, however, to connect the tops of the hot blaststoves with the chambers 29, 29, 30, 30*, although it is advisable, asadvantage is taken of the heat of the products 0 combustion leaving thechambers 29, 29, 30, 30.

The hot dry airdelivered from the hot blast stoves 10, 10*, 11, 11 isintroduced into the treating chamber 6. o the kiln, through the flues22, which deliver the heated air behind the combustion chambers 29, 2930, 30, and lines 31 located along both sides of the treating chamber,adapted to deliver air into the upper part of the treating chamber ports32, the construction of which best shown in Fig. 2.

. The chambers 29, 29, 30, 36*, are adapted to be heated by gas and airin combustion, d through branch pipes 3839 connected to pi es lit-15.The products of combustron rom the combustion chambers 29, 29, 3t), 30,are carried oil through pipe 27 to pipe 24, and thence through the pathheretofore describe to chimney fiue 20. The hot a1r from the hot blaststoves, passes over the combustion chambers 29, 29, 30, 30, whichmaterially increases the heat of the air in the kiln. Manifestly,chambers such as 29 and 29, may be located anywhere along the length ofthe chamber B, so as to impart heat to the incoming hot air anddetermine the temperature of any desired zone in such chambers. I

40 represents a flue leading from the bottom of the treating chamber tothe induction orifice of a pump 41. The eduction orifice of the pump 41is connected to a pipe 42 which discharges into the atmosphere, or maybe connected to an apparatus (not shown) suitable. for drying air and todeliver such air to the pipe 17. Apparatus for drying air is nowcommonly used in hot blast stoves, and lhave not thought it necessarytoillustrate such an apparatus in the present ap lication.

c it is sometimes desirable to introduce have not thought it necessarymoisture or a gas into the air currents entering the kiln, I provide thepipe 43 con nected to the flues 21. The moisture or gas introduced intothe flues 21, is distributed to the interior oi, the kiln in connectionwith the heated air, through the flues 22 and 32. By slightl modifyingthe construction of the kiln, t at is, the position of the fines,controlling valves, etc., they may be arranged to deliver in connectionwith the air, moisture or gases at one section of the length of thechambers A or B, as for instance the first section, and heated airwithout additional moisture or gases in the second section, and so on tothe end of a chamber. As this is an obvious change in construction,

to illustrate it. The operation of my improved kiln will bereadilyunderstood. Assuming the preliminary chamber A to be empty, and thedoors D withdrawn so as to open the left end of the chamber, orentrance, three trucks (any number of trucks may be used, depending uponthe length of the chamber) carrying apparatus to be treated, areintroduced into the chamber, and the doors-D closed, and heated thereinto the desired temperature, the heatin being efi'ected by the hot airfrom the hotgflast stoves passing through the chamber. It will beunderstood that the temperature of the air may be that derived from thehot air stoves, or that derived from the hot air stoves supplemented bythe additional temperature derived from the combustion chambers 29, 29,30, 30 within the chambers'A andB.

After the apparatus has been heated to the required temperature, thedoors F--F' between chambers and C are closed (position shown in dottedlines) and the doors D opened, and the first truck with the apparatus,advanced into the chamber C, after which the doors D are closed. Thedoors F-F' are then 0 ened (position shown in full lines) and t e doorsG closed. The workmen then enter the chamber C and apthe coatingmaterial to the apparatus under treatment by sprinkling or siftin owderthereon, or otherwise, as desire The doors FF are then again closed andthe doors D'-D opened, the apparatus which has been treated in thechamber C advanced into the secondary chamber B, at the same time thesecond truck in chamber A is advanced into the chamber C. The doors D'Dare then closed and the general steps as heretofore referred to,repeated.

The apparatus, when introduced into the chamber B is subjected to highlyheated air currents, as in chamb of the air currents, however, beingsufiicient to melt and set the coating appliedto the apparatus. When thetreated apparatus reaches the right hand end of the chamber B, the doorsD are opened which allows r cessive zones,

er A, the temperature moval of the treated apparatus from the chamber B.It will be understood that the movements of the trucks and apparatus aresuccessive and progressive longitudinally of the kiln as a whole.

It will be observed that in the preliminary and secondary heatingchambers, there are two sets of combustion chambers, 29-29 and 3030There may be more, depending u on the length of the chambers, or thecham r A may have more combustion chambers than the chamber B, or viceversa. It will be understood that the temperature at zones longitudinalof the chambers, may be increased or decreased over that of sucbyoperating or not operating certain of the combustion chambers. Forinstance, assuming it is desired that thetemperature at the right handend of the preliminary chamber A shall be greater than that at the lefthand end. the two combustion chambers 29-29 at the right hand end wouldbe operated while those at the left hand end (30-30 would not beoperated. In practice, it is desirable, in kilns of the type indicated,to have the temperature of the preliminary chamber gradually increasedfrom the inlet to the outlet, and the temperature of the secondarychamber gradually decreased from the inlet to the outlet, the purposebeing, in the preliminary chamber, to gradually heat the apparatus undertreatment, and in the secondary chamber to gradually decrease the heatof the apparatus.

I have stated that the chambers A, B and C are arranged in line, andthis is the preferable construction, but it is not essential. If, owingto lack of space, the chambers cannot be arranged in line, the chamberscan be otherwisedisposed as regards each other, as for instance, thechambers A and B at right angles, with the chamber C interposed. Suchconstruction would necessitate slightv change in'the shape of thechamber C, but not of the chambers A and B, nor would it in any wisechange the functional operation of the chambers, considered sepaiatelyor as regards each other. I have not illustrated such a construction,those skilled in the art to which this invention pertains.

as it will be obvious to It will be further understoodithat duringterior of the under treatment.

.a preliminary heatin treatment below the point at which the coatingmaterial will adhere to the apparatus Further, the apparatus undertreatment will not be subjected to cross drafts. In practice it ispossible by means of pipe 44: and damper 45 to exhaust the heated air ind introduce fresh air for the comfort of e workmen, without materiallyaltering the temperature of the apparatus during the time the coatingmaterial is being applied.

Having thus described my invention, I claim:

1. In a kiln structure, the combination of a preliminary heatingchamber, a secondary heating chamber and an interposed closed coatingchamber.

2. In a kiln structure, the combination of a preliminary heatingchamber, a secondary heating chamber, means for heating said chambers,an interposed closed coating chamber, and means for-separating theincoating chamber from the interior of the preliminary and secondaryheating chambers, during the time the coating operations are carried-.on. I

3. Ina kil a. preliminary heating. chamber, a secondary heating chamber,means for opening and-closing the outlets and inlets of said chambers, acoating chamber introduced between said for dividing said coatingchamber into three chambers during the time the coating cham her is incommunication with the interior of either the preliminary or secondaryheating chamber.

4.. In a kiln structure, the combination of g chamber, a secondaryheating chamber, means for heating-the interior of said chambers'to adifferent temperature along seetions of the length of said chambers anda coating chamber interposed betwe 11 said first name-d chambers.

5. I a kiln structure, the combination of a preliminary heating chambera secondary heating chamber, means for, heating said chambers locatedexterior to said chambers, means for adding to the heat of said chambarslocated in the interior. of said chambers, and a coating chamber locatedintermediate of said preliminary and secondary heating chambers.

6. Ina kiln structure, the combination oi" a preliminary the chambers Cand- (3 .let and outlet ary heating chamber,

n structure, the combination. of,

first namedchambers and means may be brought into heating chamber, asecondary heating chamber, doors arranged at the inlet and outlet ofsaid chambers, means for removing said doors, and a closed coatingchamber located intermediate of said heating chambers.

7. In a, kiln structure, the combination of a preliminary heatingchamber, a secondary heating chamber, doors arranged at the inof saidchambers, means for removing said doors, a coating chamber locatedintermediate of said heating-chambers and said coating chamber dividedinto three chambers, together with doors interposed getween thedivisions of the coating chamer.

8. In a kiln structure, the combination of a preliminary heatingchamber, asecond an interposed closed coating chamber, track rails insaid chambers, trucks mounted on said trackways and adapted to carry theapparatus to be treated, together with means whereby the variouschambers may be brought into communication or separated, as desired.

9. In a kiln structure, the combination of a preliminary heatingchamber, a secondary heating chamber, a coating chamber divided intothree chambers or sections, one section having its longitudinal axis inline with the longitudinal axis of the heating chambers,- and the othertwo sections disposed substantogether with means heating chambers,

and coatlng chambers whereby the heating lation.

or out of operative ref 10. A kiln, consisting of a singiestruc- I ture,divided into three normally closed chambers, i. e., a reliminary heatingchamher, a coating c amber, and a secondary heating chamber.

lLfA kiln formed as an integral structure and divided longitudinallyinto three normally closed chambers arranged in line, the first chamberbeing a preliminary heating chamber, the second a coating chamber, andthe third a secondary heating chamber.

In testimonywhereof, I aflix my signature, in the presence of twowitnesses.

GEORGE 'HILLARD BENJAMIN.

Witnesses:

HELEN E. HoELsoH, LESTER BEARDSLEY.-

